Vector OP and OQ are parallelogram sides.I need this parallelogram diagonals and their edge-top coordinates.
And if possible, then drawing too!

It's very easy, all you need is one edge-top to find!

First diag : OP + OQ =
Sec. diag : OP - OQ =

Thanks!!

Try looking at it this way. The opposite sides in a parallelogram are equal and parallel. So if the last point in your parallelogram is R then we know that vector OP and vector QR are equal. Similarly vectors OQ and PR are equal.

(Chuckles)
That diagram is not only very large, but the parallelogram is so squished that it is almost impossible to make out any details! Try reducing the size and changing the scale of the x and y axis a bit.